When a subscriber unit requests service in conventional space-based or terrestrial communication systems, the system responds by executing a visited gateway access procedure. Once a visited gateway is selected by the home gateway, the access request is forwarded to the visited gateway. The visited gateway may accept or deny access based on the location or other information about the requesting mobile. This step preserves the political sovereignty of the country in which the visited gateway is located and allows the operator of the visited gateway to accept or deny access based on it preferred criteria.
A home gateway selects a visited gateway by executing a home gateway access procedure. This procedure performs one or more geolocation measurements to determine the location of the mobile subscriber unit for the purpose of deciding whether it should be allowed access into the network (i.e., certain users may be blocked from accessing the network from certain areas). When a subscriber is provisioned for service, a service provider ID (SPID) is placed in the subscriber's subscriber unit to identify the country of origin of the subscriber. The home gateway access procedure performs calculations to locate a subscriber and checks the calculated location against a list of approved service providers. This feature permits system providers to enforce political sovereignty (e.g., country A may have a political disagreement with country B, and the home gateway access procedure allows country A to deny system access when any country B subscribers roam into country A). The location calculation is then used to compute which visited gateway should control the call. This selection is usually based on which gateway is closest to the subscriber, but other criteria may be used as well. If the home gateway allows the subscriber access, the location information is passed to the selected visited gateway, where an autonomous access decision is performed.
The visited gateway access procedure may experience considerable delay before the call is set up. Thus, there is a significant need for a system and methods that bypass the visited gateway access procedure to reduce call set up delay.